Experimental Study on the Competitive Failure of Headed Stud Connectors under Freeze-Thaw Cycles

To study the shear behavior and competitive failure mechanisms of headed stud connectors in steel-concrete composite (SCC) structures under the influence of freeze- thaw cycles (FTCs), the material performance test of C60 concrete after FTCs and the pushout test of 36 miniaturized specimens of headed stud connectors under FTCs were carried out. After various FTCs, the cubic compressive strength and dynamic elastic modulus of C60 concrete were measured. In the pushout tests, special attention was given to studying the failure modes, load-slip curves, shear capacity, and shear stiffness of stud connectors. A revised method for calculating the shear capacity of headed stud connectors, considering the effects of FTCs, is suggested based on current design codes. The study findings indicate that the performance of stud connectors is adversely affected by FTCs, leading to a degradation in their shear capacity and stiffness. As the FTCs' effect intensifies, the two failure modes, stud shearing and concrete cracking, undergo alterations.